
determine the probabilities in simple multistage probability situations

apply the law of large numbers to probability situations.
In simple, multistage chance situations (where the events are independent), learners can determine probabilities by using, for example, systematic lists or twoway arrays (tables).
Learners can recognise complementary and mutually exclusive events. For example, a learner knows that when two dice are rolled, ‘double’ and ‘not a double’ are both complementary (one or other must occur) and mutually exclusive (they can’t both occur) events.
Learners know there are situations in which probabilities cannot be determined theoretically. In such cases, the relative frequency of an event can be used to estimate its probability.
Learners know that, in determining the relative frequency of an event, the greater the number of trials, the more accurate the estimate (this is the law of large numbers). For example, the accuracy of a particular weather forecaster can’t be determined from a single forecast.
Theoretical probability
Learners develop their understanding of the difference between theoretical and experimental probabilities.
Using frequencies to predict
Learners use the frequencies of outcomes to predict the likelihood that an event will occur, and learn that probabilities are not absolute predictors in the short run.